The person who owns the car title is who should get the money. The person who insures the car may show economic interest in the vehicle but not ownership. If the person who has insurance on the car leaves it, stop paying insurance or gets in an accident without insurance the person on the title is still liable. The owner of the actual property legally is what really counts.
This is why when a car is totaled the insurance company has to secure the title. They can only get the title from an owner. You are not asked to produce a car title to get insurance just the VIN number. It does not matter the state although most states will require that you title a car in the state you insure it in.
These types of situations can get very complicated but it does not change the law of ownership. It is the same way you finance a car and you insure it but the physical car is owned by the bank. This way if you stop making the payments they can legally seize the vehicle by being the lien holder on the title or as a co-owner on the title. When it comes to money the bottom line is ownership.